|Title||Drag Reduction Over Rough Surfaces|
|Project(s)||No Simula project|
|Publication Type||Master's thesis|
|Year of Publication||2008|
|Degree awarding institution||NA|
|Publisher||Chalmers University of Technology|
The main objective with this thesis is to derive drag force reduction, for moderate Reynolds numbers, when a microscopic rough surface of height +u0190 is introduced over a flat plate. Such a problem is often impossible to treat with numerical methods since the microscopic scale is much smaller than the macroscopic scale which is present in the same equation. To overcome this problem, a homogenization process is performed on the rough surface and an effective (approximate) equation is obtained, which is an O(+u01902 ) approximation. This effective equation describes the flow at the macroscopic scale but it captures the flow characteristics in the microscopic scale through a constant coefficient operator. Given the effective equation, the drag force reduction is then derived.